WINTEC Easy Change Gullet A new saddle? Or new head iron? An easy decision! The easy-change head iron system simplifies the change of the chamber width of your saddle for individual adjustment to the withers of your horse - easy to use No screws. To replace and customise your Wintec saddle. Chamber width 27/28 = yellow, chamber width 29 = green, chamber width 30 = black, chamber width 31 = blue, chamber width 32 = red, chamber width 33/34 = white.